Lake Landscape Research Articles

Spatial Distribution and Driving Factors of Nitrogen Cycle Genes in Urban Landscape Lake

Urban landscape lakes are increasingly at risk of nitrogen-induced eutrophication. Microbial nitrogen transformation plays a crucial role in reducing nitrogen levels in these lakes. However, the relationships between microbial communities, nitrogen functional genes, and nitrogen dynamics in water and sediment, along with their underlying mechanisms, remain unclear. In this study, we systemically investigated the spatial distributions of physicochemical indicators in the overlying water and sediment in a typical urban landscape lake, Zizhuyuan Park, and the microbial communities and nitrogen cycling genes in the surface sediments of the lake connection (CO), side (SI), and center (CE) were evaluated via macrogenetic sequencing technology to analyze their relationships with environmental factors. The results revealed that the concentrations of TN, NO3−, and NH4+ in the lake water were within the ranges of 1.36~2.84, 0.98~1.92, and 0.01~0.29 mg·L−1, respectively. The concentrations of TN, NO3−, and NH4+ in the sediments ranged from 1.17~3.47 g·kg−1, 0.88~1.94 mg·kg−1, and 5.61~10.09 mg·kg−1, respectively. The contents of NH4+ in water, TN and NO3− in sediments were significantly different in spatial distribution (p < 0.05). At the CE site, the Shannon diversity index was the highest and differed significantly from the values at the SI and CO sites (p < 0.01).The sediments of Central Lake contained a total of 36 phyla and 1303 genera of microorganisms. Proteobacteria (62.88–64.83%) and Actinobacteria (24.84–26.62%) accounted for more than 85% of the microorganisms. Nitrospirae, Ignavibacteriae, and Bacteroidetes were significantly different (p < 0.05) at the CE, and Planctomycetes were significantly different (p < 0.05) at the CO. The functional gene nrfA exhibited the highest abundance, followed by napA, nosZ, nirS, hao, ureC, norB, nifH, nirK, hdhA, nifB, and amoA. The abundances of hao and nifH differed significantly at various locations in Central Lake (p < 0.05). The key nitrogen transformation processes in the sediments, ranked by contribution rate, were DNRA, denitrification, nitrification, ammoniation, nitrogen fixation, and anammox. The six nitrogen processes showed significant differences (p < 0.01) in spatial distribution. The pH, TN, NO3−, NH4+, C/N ratio of the sediment, and NH4+ in the lake water impact the microbial community and nitrogen conversion process. The sediment should be cleaned regularly, and the water cycle should be strengthened in urban landscape lakes to regulate microorganisms and genes and ultimately reduce nitrogen and control eutrophic water. This study can provide a reference for improving and managing lake water environments in urban landscapes.

Impact of recharge water source quality on Chlorella vulgaris growth and biomass: Strategies for eutrophication control in urban landscape lakes

Understanding the relationship between recharge water quality and algal metabolism is critical for managing eutrophication in urban landscape water bodies. This study investigates six landscape water bodies in Xi'an City, utilizing natural and reclaimed water recharge sources to cultivate and evaluate the growth and biomass composition of Chlorella vulgaris. The findings revealed that the growth and metabolic rate of C. vulgaris were faster in reclaimed water sources, whereas nitrogen (N) and phosphorus (P) conversion rates were higher in natural water sources. Redundancy and statistical analyses indicated that total nitrogen (TN) in reclaimed water was a major factor influencing C. vulgaris growth, contributing 74.3 % to its growth dynamics. In contrast, natural water sources did not significantly affect the growth characteristics of C. vulgaris. The biomass characteristics of C. vulgaris across different recharge water sources were similar, exhibiting a strong correlation with water quality. Environmental factors such as COD, N/P ratio, and PO4-P contributed most significantly to biomass accumulation. These findings provide a strategy for preventing and controlling eutrophication in landscape water bodies that utilize reclaimed water recharge sources in Xi'an City.

Effects of artemisinin sustained-release algaecides on in-situ cyanobacterial inhibition and microbes-floating plants dominated ecosystem functions in artificial landscape lake

The artemisinin sustained-release algaecides (ASAs) have been proven to be a safe and effective mean of inhibiting cyanobacteria in laboratory experiments. However, their effectiveness and impacts on ecosystem functions (EF) in natural waters are still unclear. In this study, the in-situ inhibitory effect of ASAs on cyanobacteria in natural waters was investigated over a period of 110 days to assess EF impacts dominated by microbes and floating plants. The results indicated that ASAs had a long-term inhibitory effect on cyanobacteria. ASAs did not affect sediment but increased TOC and TP in the water column in 2–10 days. Microbial diversity and network analyses indicated that ASAs enhanced bacterial diversity, network complexity, and hub-bacteria in networks. Metabolic pathway predictions and CCA analysis showed that ASAs maintained the stability of EF by enhancing the metabolic capacities of bacteria, and the relationships between metabolic microorganisms and environmental factors. PLS-PM revealed that ASAs primarily drove bacterial resistance to cyanobacteria, which was the key mechanism for its long-term inhibition of cyanobacteria. However, the early outbreak of floating plants was not conducive to the long-term inhibition of cyanobacteria by ASAs. This study provides new insights into the mechanisms and ecological impacts of cyanobacterial inhibition by ASAs in complex aquatic environments.

Spatio-temporal change and driving mechanisms of land use/cover in Qarhan Salt Lake area during from 2000 to 2020, based on machine learning

The significance of land use classification has garnered attention due to its implications for climate and ecosystems. This paper establishes a connection by introducing and applying automatic machine learning (Auto ML) techniques to salt lake landscape, with a specific focus on the Qarhan Salt Lake area. Utilizing Landsat-5 Thematic Mappe (TM) and Landsat-8 Operational Land Imager (OLI) imagery, six machine learning algorithms were employed to classify eight land use types from 2000 to 2020. Results show that XGBLD performed optimally with 77% accuracy. Over two decades, salt fields, construction land, and water areas increased due to transformations in saline land and salt flats. The exposed lakes area exhibited a rise followed by a decline, mainly transforming into salt flats. Agricultural land areas slightly increased, influenced by both human activities and climate. Our analysis reveals a strong correlation between salt fields and precipitation, while exposed lakes demonstrate a significant negative correlation with evaporation and temperature, highlighting their vulnerability to climate change. Additionally, human water usage was identified as a significant factor impacting land use change, emphasizing the dual influence of anthropogenic activities and natural factors. This paper addresses the void in the application of Auto ML in salt lake environments and provides valuable insights into the dynamic evolution of land use types in the Qarhan Salt Lake region.

Sensitivity Analysis of Urban Landscape Lake Transparency Based on Machine Learning in Taiyuan City

This article addresses the challenge of maintaining water quality in urban landscape lakes in water-scarce cities using transparency as the key indicator. The sensitivity of water transparency to nine water quality parameters, including chlorophyll a and inorganic suspended solids, in 16 urban landscape lakes of the city of Taiyuan was evaluated using the Sobol and Morris sensitivity analysis methods. The results indicate that for water bodies supplied by surface water, critical factors include chlorophyll a and hydraulic retention time. For water bodies supplied by tap water, inorganic suspended solids and total phosphorus are more significant. Water bodies with a dual function of urban flood control should focus on dissolved oxygen, ammonium nitrogen, and chemical oxygen demand. Based on these findings, targeted management strategies are proposed to enhance algae management, control suspended solids input, and adjust water retention times, aiming to improve the transparency and quality of Taiyuan’s urban landscape.

A Survey of Changes in Grasslands within the Tonle Sap Lake Landscape from 2004 to 2023

A Survey of Changes in Grasslands within the Tonle Sap Lake Landscape from 2004 to 2023

Digital twin-based virtual modeling of the Poyang Lake wetland landscapes

Virtual wetland landscapes of provide fundamental support for digital twin watershed constructions. However, most digital twin applications in natural environments have focused on static digital scenes and little consideration for wetlands. The Poyang Lake is characterized by seasonal hydrologic changes, with periodic plant community successions, making it necessary to capture dynamic changes in the Poyang Lake ecological landscapes through dynamic three-dimensional (3D) scenes. This study selected typical landscapes to establish digital twin scenarios, presenting the virtual landscapes, distribution characteristics of flora and fauna in the Poyang Lake wetland, and seasonal changes in the lake water levels. The results can be used to restore the virtual Poyang Lake landscapes, including seasonal changes in the water surface, vegetation growth, and migratory bird activities. This construction process can be applied to similar digital twin constructs for flood-prone wetland watersheds, providing insights into digital twin watersheds or nature-oriented digital twin development.

Impacts of hydrologic management on the eutrophication of shallow lakes in an intensive agricultural landscape (Saskatchewan, Canada)

Abstract Hydrologic management of shallow lakes is often undertaken to prevent fluctuations in lake level, and to ensure sufficient water volume for economic, domestic, and recreational uses, but there is inconsistent evidence of whether lake‐level stabilisation through hydrological management promotes or hinders eutrophication. Here we used multi‐proxy paleolimnological assessments of water quality (sedimentary carbon, nitrogen, total phosphorus, fossil pigments), and zooplankton community ecology (fossil Cladocera assemblages), combined with Landsat‐derived estimates of lake surface area in two shallow eutrophic lakes, in the Prairies of southern Saskatchewan, Canada, to quantify how 8 decades of contrasting hydrological management strategies (continuous or intermittent) affect primary production and phytoplankton composition. Analysis revealed that irregular hydrological management of Pelican Lake led to sharp increases in primary production concomitant with lake‐level decline. In contrast, continuously managed Buffalo Pound Lake, a drinking water reservoir for regional cities, exhibited slow, persistent eutrophication over decades despite active regulation of water levels. In both lakes, strong correlations of δ 15N values with pigments from diazotrophic cyanobacteria (canthaxanthin) showed that N2‐fixation increased during eutrophication irrespective of the timing of change. Finally, variation in fossil cladoceran density and composition reflected changes in pelagic and littoral habitats (e.g., reduced macrophyte cover) due to changes in both lake level and water quality. Basin comparison shows that while hydrologic management can moderate water quality degradation due to lake‐level change, it does not prevent eutrophication when nutrient influx remains high. Given that regional water availability is forecast to decline in coming decades, we anticipate that continued hydrological management will be unavoidable and will be unable to improve water quality unless nutrient influx is also controlled.

A 1 Ma sedimentary ancient DNA (sedaDNA) record of catchment vegetation changes and the developmental history of tropical Lake Towuti (Sulawesi, Indonesia).

Studying past ecosystems from ancient environmental DNA preserved in lake sediments (sedaDNA) is a rapidly expanding field. This research has mainly involved Holocene sediments from lakes in cool climates, with little known about the suitability of sedaDNA to reconstruct substantially older ecosystems in the warm tropics. Here, we report the successful recovery of chloroplast trnL (UAA) sequences (trnL-P6 loop) from the sedimentary record of Lake Towuti (Sulawesi, Indonesia) to elucidate changes in regional tropical vegetation assemblages during the lake's Late Quaternary paleodepositional history. After the stringent removal of contaminants and sequence artifacts, taxonomic assignment of the remaining genuine trnL-P6 reads showed that native nitrogen-fixing legumes, C3 grasses, and shallow wetland vegetation (Alocasia) were most strongly associated with >1-million-year-old (>1 Ma) peats and silts (114-98.8 m composite depth; mcd), which were deposited in a landscape of active river channels, shallow lakes, and peat-swamps. A statistically significant shift toward partly submerged shoreline vegetation that was likely rooted in anoxic muddy soils (i.e., peatland forest trees and wetland C3 grasses (Oryzaceae) and nutrient-demanding aquatic herbs (presumably Oenanthe javanica)) occurred at 76 mcd (~0.8 Ma), ~0.2 Ma after the transition into a permanent lake. This wetland vegetation was most strongly associated with diatom ooze (46-37 mcd), thought to be deposited during maximum nutrient availability and primary productivity. Herbs (Brassicaceae), trees/shrubs (Fabaceae and Theaceae), and C3 grasses correlated with inorganic parameters, indicating increased drainage of ultramafic sediments and laterite soils from the lakes' catchment, particularly at times of inferred drying. Downcore variability in trnL-P6 from tropical forest trees (Toona), shady ground cover herbs (Zingiberaceae), and tree orchids (Luisia) most strongly correlated with sediments of a predominantly felsic signature considered to be originating from the catchment of the Loeha River draining into Lake Towuti during wetter climate conditions. However, the co-correlation with dry climate-adapted trees (i.e., Castanopsis or Lithocarpus) plus C4 grasses suggests that increased precipitation seasonality also contributed to the increased drainage of felsic Loeha River sediments. This multiproxy approach shows that despite elevated insitu temperatures, tropical lake sediments potentially comprise long-term archives of ancient environmental DNA for reconstructing ecosystems, which warrants further exploration.

Automatic Group Decision-Making for Algal Bloom Management Based on Information Self-Learning

The phenomenon of algal bloom seriously affects the function of the aquatic ecosystems, damages the landscape of urban river and lakes, and threatens the safety of water use. The introduction of a multi-attribute decision-making method avoids the shortcomings of traditional algal bloom management that relies on manual experience. However, the weight-calculation part of this method still receives the artificial influence of human factors, which reduces the accuracy and scientific rigor of the decision. This paper presents a group decision-making method based on information self-learning which makes decision weights automatically clustered and assigned. A general framework of decision-making management is constructed for the algal bloom management process. In the decision-making process, an improved density-based clustering algorithm is used to automatically cluster and rank the decision data in the form of the three-parameter interval number, and ultimately obtain the optimal management method that meets the management objectives. Finally, the method was applied at the monitoring station of Sanjiadian Reservoir in Beijing, China. Based on the treatment objectives and water quality monitoring data of the station, relevant experts were invited to evaluate the management solutions, and the information self-organizing algorithm of this paper was used to automatically rank the decision-making methods, and finally obtain the most suitable management method for the station. Comparison with the water quality data and treatment inputs after the previous man-made selection of treatment options, and discussion among experts, show that the decision-making method is feasible and effective, and contributes to the sustainable treatment of algal blooms.

Governance Index for Prioritisation of Afrotropical Inland Lakes for Conservation and Sustainability

ABSTRACTExisting scientific methods can be combined with insights on the socio‐ecological landscape of Afrotropical lakes to provide better policy options for stakeholders and to develop more efficient resource management strategies. Using integrated African resource and ecosystem maps and an approach for the developed Governance Index for Prioritisation (GIP) of Lake Victoria resources, our study highlights prospects for adopting the GIP methodology to increase understanding and management of Afrotropical lakes. The use of GIP is recommended for adoption and promotion in areas where such approaches appear defensible for the assessment of lake‐wide practices, and in areas with robust indigenous knowledge to provide a broad view of the ecological health of the Afrotropical ecosystem.

Characterization of CH<sub>4</sub> fluxes in urban landscape lakes at different time scales and analysis of influencing factors—A case of Lake Mochou in Nanjing City

Characterization of CH<sub>4</sub> fluxes in urban landscape lakes at different time scales and analysis of influencing factors—A case of Lake Mochou in Nanjing City

Widespread evidence for elephant exploitation by Last Interglacial Neanderthals on the North European plain.

Neanderthals hunted and butchered straight-tusked elephants, the largest terrestrial mammals of the Pleistocene, in a lake landscape on the North European plain, 125,000 years ago, as recently shown by a study of the Last Interglacial elephant assemblage from Neumark-Nord (Germany). With evidence for a remarkable focus on adult males and on their extended utilization, the data from this location are thus far without parallel in the archaeological record. Given their relevance for our knowledge of the Neanderthal niche, we investigated whether the Neumark-Nord subsistence practices were more than a local phenomenon, possibly determined by local characteristics. Analyzing elephant remains from two other Last Interglacial archaeological sites on the North European plain, Gröbern and Taubach, we identified in both assemblages similar butchering patterns as at Neumark-Nord, demonstrating that extended elephant exploitation was a widespread Neanderthal practice during the (early part of the) Last Interglacial. The substantial efforts needed to process these animals, weighing up to 13 metric tons, and the large amounts of food generated suggest that Neanderthals either had ways of storing vast amounts of meat and fat and/or temporarily aggregated in larger groups than commonly acknowledged. The data do not allow us to rule out one of the two explanations, and furthermore both factors, short-term larger group sizes as well as some form of food preservation, may have played a role. What the data do show is that exploitation of large straight-tusked elephants was a widespread and recurring phenomenon amongst Last Interglacial Neanderthals on the North European plain.

Effects of habitat heterogeneity on bird communities in the forests of northeastern Germany

Habitat heterogeneity is a key factor for regulating biodiversity in temperate lowland forests. Specifically, stands associated with late forest development phases provide important habitat structures for many rare and threatened forest bird species. However, how forest stands that differ in their structural complexity, canopy conditions and tree species composition affect forest bird assemblages both at the local and landscape scale remains largely unclear. In a young moraine lake landscape of northeastern Germany, we assessed correlations of bird diversity and bird composition with stand properties. We used data from 48 transects (400 m) established in (1) unmanaged, closed-canopy, mature stands that were dominated by Fagus sylvatica (UDS), and (2) diverse managed, mixed coniferous stands with a mosaic of open and closed canopy patches (MCS). We found that bird communities of the UDS strongly differed from those in the MCS, with open habitat species being more frequent in the MCS. By contrast, differences in diversity measures were less distinct. Moreover, we identified nine indicator species for the UDS (Columba oenas, Cyanistes caeruleus, Muscicapa striata, Leiopicus medius, Certhia brachydactyla, Ficedula parva, Dryobates minor, Sturnus vulgaris, Ficedula hypoleuca) and seven indicator species for the MCS (Periparus ater, Pyrrhula pyrrhula, Regulus regulus, Prunella modularis, Lophophanus cristatus, Emberiza citronella, Anthus trivialis). Several famous ancient beech forest patches in Müritz National Park and the UNESCO Biosphere Reserve “Schorfheide-Chorin” were found to harbour the set of the UDS indicator species. The UDS support of bird coenosis is typical for old mature broadleaved forests and can be considered as an effective tool for bird conservation. Our results further indicate that the combination of unmanaged and managed stands associated with different habitat complexities would benefit forest bird assemblages at the landscape scale. Key words: forest specialist birds, bird conservation, non-managed forests, old-growth patches, Ficedula parva, Leiopicus medius, coniferous forest

Identifying ARG-carrying bacteriophages in a lake replenished by reclaimed water using deep learning techniques

As important mobile genetic elements, phages support the spread of antibiotic resistance genes (ARGs). Previous analyses of metaviromes or metagenome-assembled genomes (MAGs) failed to assess the extent of ARGs transferred by phages, particularly in the generation of antibiotic pathogens. Therefore, we have developed a bioinformatic pipeline that utilizes deep learning techniques to identify ARG-carrying phages and predict their hosts, with a special focus on pathogens. Using this method, we discovered that the predominant types of ARGs carried by temperate phages in a typical landscape lake, which is fully replenished by reclaimed water, were related to multidrug resistance and β-lactam antibiotics. MAGs containing virulent factors (VFs) were predicted to serve as hosts for these ARG-carrying phages, which suggests that the phages may have the potential to transfer ARGs. In silico analysis showed a significant positive correlation between temperate phages and host pathogens (R = 0.503, p < 0.001), which was later confirmed by qPCR. Interestingly, these MAGs were found to be more abundant than those containing both ARGs and VFs, especially in December and March. Seasonal variations were observed in the abundance of phages harboring ARGs (from 5.62 % to 21.02 %) and chromosomes harboring ARGs (from 18.01 % to 30.94 %). In contrast, the abundance of plasmids harboring ARGs remained unchanged. In summary, this study leverages deep learning to analyze phage-transferred ARGs and demonstrates an alternative method to track the production of potential antibiotic-resistant pathogens by metagenomics that can be extended to microbiological risk assessment.

Effects of water environmental factors and antibiotics on bacterial community in urban landscape lakes

The presence of antibiotics can affect the natural microbial community and exert selective pressure on the environment's microorganisms. This study focused on three types of urban landscape lakes in Xi'an that were closely related to human activities. By combining basic water quality indicators, antibiotic occurrence status, bacterial communities and their potential metabolic functions, Spearman correlation coefficient and redundancy analysis were used to explore the relationship between them, and further explore the impact mechanism of environmental factors and antibiotics on bacterial community structure. The results showed that ofloxacin, erythromycin, and roxithromycin were the main types of antibiotics in the three landscape lakes, with low ecological risks, and there was a clear clustering of antibiotic occurrence. Proteobacteria was the most abundant bacterial phylum, and each lake had its own unique dominant bacteria, which indicates that they are influenced by varying water sources, pollution, and other nearby environments. Statistical analysis showed that pH and nitrogen nutrients were the most critical environmental factors affecting bacterial communities (P<0.01), while tetracyclines and lincomycins were the antibiotics that had a significant impact on bacterial communities (P<0.05). Antibiotics mainly promote defense- and signal transduction-related functions, and inhibit the metabolic activity of bacterial communities. However, the impact of antibiotics on bacterial diversity, community structure, and potential metabolic function in the three urban lakes was less than that of environmental factors. These results help to clarify the mechanism and degree of impact of different interference factors (environmental factors, conventional pollutants, and antibiotics) on bacterial communities in the water environment and are important for the management of urban landscape lake water environments.

Freshwater fish diversity in the western Amazon basin shaped by Andean uplift since the Late Cretaceous

South America is home to the highest freshwater fish biodiversity on Earth, and the hotspot of species richness is located in the western Amazon basin. The location of this hotspot is enigmatic, as it is inconsistent with the pattern observed in river systems across the world of increasing species richness towards a river’s mouth. Here we investigate the role of river capture events caused by Andean mountain building and repeated episodes of flooding in western Amazonia in shaping the modern-day richness pattern of freshwater fishes in South America, and in Amazonia in particular. To this end, we combine a reconstruction of river networks since 80 Ma with a mechanistic model simulating dispersal, allopatric speciation and extinction over the dynamic landscape of rivers and lakes. We show that Andean mountain building and consequent numerous small river capture events in western Amazonia caused freshwater habitats to be highly dynamic, leading to high diversification rates and exceptional richness. The history of marine incursions and lakes, including the Miocene Pebas mega-wetland system in western Amazonia, played a secondary role.

Identifying the drivers of chlorophyll-a dynamics in a landscape lake recharged by reclaimed water using interpretable machine learning

The water quality of lakes recharged by reclaimed water is affected by both the fluctuation of reclaimed water quality and the biochemical processes in the lakes, and therefore the main controlling factors of algal blooms are difficult to identify. Taking a typical landscape lake recharged by reclaimed water as an example and using the spatiotemporal distribution characteristics and correlation analysis of water quality indexes, we propose an interpretable machine learning framework based on random forest to predict chlorophyll-a (Chl-a). The model considered nutrient difference indexes between reclaimed water and lake water, and further used feature importance ranking and partial dependence plot to identify nutrient drivers. Results show that the NO3−-N input from reclaimed water is the dominant nutrient driver for algal bloom especially at high temperatures, and the negative correlation between NO3−-N and Chl-a in the lake water is the consequence of algal bloom rather than the cause. Our study provides new insights into the identification of eutrophication factors for lakes recharged by reclaimed water.

Will they be back? A framework to guide rare macrophyte conservation decisions in lakes

Shallow lake restoration typically focusses on the re‐establishment of macrophytes. The likelihood of a species returning to a site is contingent on dispersal, proximity to propagule sources, and the on‐site propagule‐bank viability. We explore the potential of palaeoecological records in combination with botanical surveys and distribution maps, to ascertain the loss of three submerged macrophytes (Littorella uniflora, Najas flexilis, and Elatine hydropiper) from, respectively, two lakes (Barton Broad, Norfolk and Esthwaite Water, Cumbria) and one lake landscape (Greater Glasgow, Scotland). We discuss re‐establishment likelihood when accounting for species' autoecology and current water‐chemistry conditions. L. uniflora is widespread in the United Kingdom but absent locally in Norfolk without known seed bank, hence is unlikely to naturally recolonise Barton Broad. Furthermore, current conditions are unsuitable for this species suggesting that nutrient reduction is required prior to translocation. N. flexilis is extinct in Cumbria and the long distances involved (&gt;100 km) for recolonisation of Esthwaite Water suggest that spatial dispersal is unlikely, rendering the seed bank the last chance of natural recovery. Alternatively, translocation may be feasible. E. hydropiper is a nationally scarce species in the United Kingdom yet would have only a short dispersal distance (~10 km) to recolonise Loch Libo, hence there being no requirement for translocation. In exploring the recovery possibilities for the three focal plant species, we develop a time–space integrated framework that can be employed to guide conservation decisions for other species, enabling a more rational use of translocations in the future, in line with international guidelines.

Temporal variations in reactive oxygen species in biofilms of submerged macrophytes: The key role of microbial metabolism mediated by oxygen fluctuations

Reactive oxygen species (ROS) play a crucial role in the biogeochemistry of aquatic environments, yet their occurrence and accumulation in the biofilm of submerged macrophytes have been poorly documented. Herein, we first investigated the light-dark cycling fluctuations of biofilm microenvironment and the temporal variations of a representative ROS (O2•−) during biofilm succession on the macrophyte leaves and subsequently quantified the photochemical processes in biofilms. The sustained production of O2•− exhibited a distinct rhythmic fluctuation from 32.49 ± 0.56 μmol/kg to 72.56 ± 0.92 μmol/kg FW, which simultaneously fluctuated with the dissolved oxygen, redox potential, and pH, all driven by the alternating oxic-anoxic conditions of biofilms. The intensities of O2•− and ROS firstly increased and then decreased throughout biofilm succession. The O2•− concentrations in biofilms from different waters followed the order of rural river water > landscape lake water > aquaculture pond water, and the leaf photosynthesis and microbial community played a key role. ROS production was significantly associated with Actinobacteria, Proteobacteria and Bacteroidetes, with contributions of 44.6%, 32.8%, and 15.2%, respectively. Partial least squares path modeling structural equation analysis showed that ROS production in leaf biofilms was mainly related to the microenvironment and microbial metabolism. These findings will facilitate the development of ecological restoration strategies in aquatic environments.